Selective and proportional hydraulic remote control device, in particular for handling and public work gears

Abstract

A selective and proportional hydraulic remote control device including jacks which are connected to a high pressure oil circuit commutated by distributors. The distributors are remotely controlled by a low pressure circuit which is connected to a fluid emitter. The emitter causes the input flow of the low pressure circuit for the distributors to vary. Only the input to the low pressure circuit takes place from the emitter through connections, while the return to the tank takes place from the distributors through jets, the sections of which are fixed. The same distributor can be controlled from several different locations.

We claim: 
     
       1. A fluid control device comprising, in combination: two fluid emitters which are substantially identical, each said emitter including body means and piston means;   said body means including a first port, a second port, and a third port;   a source of fluid operably connected to said fluid emitters;   said piston means being mounted in said body means for displacement therein;   said piston means being normally biased to a first position so that the first port, through which fluid from said source of fluid may be introduced into said fluid emitter, is closed, while the fluid which may flow from the third port is permitted to leave said fluid emitter through said second port;   said piston means being movable by an external force to a second position so that fluid from said source of fluid which is introduced into said fluid emitter through said first port is permitted to leave said fluid emitter through said third port, while the second port is closed;   said piston means being provided with control means for varying the effective fluid communication passageway between said first port and said third port;   a distributor provided with two ports which are alternatively inlet and outlet ports, each of said two ports being connected to one of said third ports of said two fluid emitters;   said fluid emitters allow in particular the admission of the fluid sent under low pressure toward said distributor connected to said fluid emitters through an inlet port of said distributor, wherein said distributor is adapted to control operation of power members, such as jacks or the like;   said control means of one of said emitters adjusts the pressure to the inlet port of said distributor, while the pressure of an outlet port of said distributor is constant;   said control means which adjusts the pressure of the inlet port of said distributor are grouped inside said fluid emitter;   said fluid emitter includes a body provided with at least one hollow piston which slides inside an axial bore in said body;   said control means includes calibrated holes drilled in a radial direction in said piston;   said two fluid emitters being alternatively manually operated by means of a control lever;   the position of said control lever defines the number of said calibrated holes being obturated, the unobturated holes defining a section of said inlet port by opening in a chamber of pressure;   said distributor having a slide valve with two opposite end faces, and each port of said distributor opens in a chamber in which is located one of said two opposite end faces of said slide valve;   said slide valve including a hole along its longitudinal axis extending from one of said end faces to the other of said end faces of said slide valve; and   said hold being provided with a jet through which a controlled flowing out of said fluid set under low pressure takes place.